> I'm looking for some information on this function, but have been
> unsuccessful so far. Does anyone know whether this function causes
> or schedules a context switch to the process being woken up?

It marks processes blocked in a select() or poll() call for the thing
in the selinfo parameter runnable. This may involve a call to wakeup(),
if multiple processes are waiting.

The scheduler may pick one of the now runnable processes the next time it is
doing a context switch. AFAICT there is no imediate switch to the process
enforced.

Martin